1. Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan
2. Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan
3. Institute of Medicine, Chung Shan Medical University, Taichung 402, Taiwan
4. Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077
5. Tissue Culture Center, New York Eye and Ear Infirmary, New York Medical College, New York, NY 10009, USA